1. Field of the Invention
The invention relates to machine elements, supports and electrical motor structures generally and in particular to a gear motor with either a plastic or a resin box and an integral supporting bracket.
2. Discussion of the Prior Art
In a known deployment apparatus on a school bus with a swinging safety device, a metallic gear box is attached to a separate, generally L-shaped, metallic bracket with multiple nuts and bolts. The gear box and the attached bracket are secured inside the deployment apparatus from which the safety device extends when a gear motor is activated by the driver. Different devices may be used for mounting the safety device to the deployment apparatus on the school bus.
For example, inside the deployment apparatus, one L-shaped bracket attached to a known gear box includes open-ended slots. However, these slots allow the L-shaped bracket carrying the gear box to disengage from inside the deployment apparatus if the mounting nuts and bolts are jarred loose. See FIG. 4 of U.S. Pat. No. 5,132,662 issued to Burch on Jul. 21, 1992.
In FIG. 1, a typical school bus 10 has front lights 12 and a front bumper 14. Flashing safety stop lights 16 are lit when the school bus 10 is stopped to take on or discharge passengers through a front door (not shown). A rear door (also not shown) is used only in the event of an emergency. When the school bus 10 is stopped for passengers entering and exiting, a guard arm 15 is extended from a first deployment apparatus 20 mounted on the front bumper 14 and a stop sign 18 is extended from a second similar deployment apparatus 20 mounted on a side wall 19 of the school bus 10. The guard arm 15 is shown in phantom lines in a normally retracted position resting on the first deployment apparatus 20 mounted on the front bumper 14. When activated by the driver, the guard arm 15 is extended by swinging outwardly approximately 90° to the deployed position shown in solid lines in FIG. 1.
In FIG. 2, the stop sign 18 is shown in a normally retracted position resting on the second deployment apparatus 20 mounted on the side wall 19. Lights 22 on the stop sign 18 are also illuminated when the stop sign 18 is extended by swinging outwardly at approximately 90° angle to the deployed position shown in FIG. 1.
In FIG. 3, there is shown a prior art device covered by U.S. Pat. No. 5,406,250 which was issued to Reavell et al. on Apr. 11, 1995. In this prior art device, a vertical connector 24 has top and bottom flanges 25 pivotally secured inside respective top and bottom sides 26 of the second deployment apparatus 20 via pivot pins 30. In addition to the sides 26, the second deployment apparatus 20 has an inside wall 29 and an outside cover 31. The apparatus 20 encloses a friction clutch (not shown) to be described below for moving the vertical connector 24. This stop sign 18 is pivoted to the deployed state of FIG. 3 from the retracted state of FIG. 2 by a link 32 under the cover 31 of the apparatus 20.
In FIG. 4, there is another prior art device covered by U.S. Pat. No. 5,132,662 which was issued to Burch on Jul. 21, 1992. The top side 26 has mounted thereto a friction clutch 36 for the stop sign (not shown) which is secured to the vertical connector 24 by bolts 27. A steel torsion spring 50 surrounds the friction clutch 36 and controls the torque of the clutch 36. The top and bottom flanges 25 of the vertical connector 24 are pivotally secured outside the respective top and bottom sides 26 of the deployment apparatus by the pivot pins 30. A nut 34 and a washer 48 secure the upper pivot pin 30 into position. This upper pivot pin 30 extends downwardly through the friction clutch 36, an L-shaped bracket 38 and a gear box 40. Nuts 42 and bolts 44 attach the gear box 40 to the L-shaped bracket 38. A motor 46 drives the gears (not shown) inside the box 40 when activated through two electric wires 49 by the driver of the school bus.
FIG. 5 is a partial cross-sectional view of the prior art structure shown in FIG. 4. From top to bottom in FIG. 5, there is illustrated the pivot pin 30, the nut 34, the washer 48, the top flange 25, the friction clutch 36, the ring 50, the L-shaped bracket 38, the bolts 44, the nuts 42, the gear box 40, the motor 46 and the electric wire 49.
The operation of the prior art device shown in FIGS. 4 and 5 may be described as follows. When the motor 46 in FIG. 5 is energized through the electric wire 49 by the driver, the gears (not shown) inside the box 40 are turned to rotate an output shaft 53 engaged with the friction clutch 36 which turns the pivot pin 30 together with the nut 34, the washer 48 and the top flange 25. Referring now to FIG. 4, the top flange 25 is formed integrally with the vertical connector 24 and the bottom flange 25. So, when the top flange 25 rotates out of its retracted position, the vertical connector 24 rotates also and carries with it the bolts 27 to which are secured the stop sign 18 seen in FIGS. 1–3. Thus, the stop sign 18 is extended. Returning to FIG. 4, when the driver actuates a switch (not shown) that reverses the current to the two electric wires 49, the motor 46 returns the stop sign, the vertical connector 24, the top flange 25 and the friction clutch 36 to their retracted positions.
Referring to FIG. 5, the L-shaped bracket 38 is shown with two open-ended slots 52. Bolts 54, nuts 56 and washers 58 extend through the two slots 52 to secure the L-shaped bracket 30 to the inside wall 29 of the second deployment apparatus 20, best seen in FIG. 3. As one may imagine from viewing FIG. 5, constant vibration and jarring may loosen the nuts 56 and cause the L-shaped bracket 38 to slide down due to slippage of the bolts 54 along the open-ended slots 52, so that the pivot pin 30 disengages from the friction clutch 36. Likewise, constant vibration and jarring may loosen the nuts 42 and cause the L-shaped bracket 38 to separate due to unfastening of the bolts 44, so that the gear box 40 disengages from the L-shaped bracket 38.
These problems in the prior art could not be solved by the gear boxes disclosed in U.S. Design Pat. No. D451,072 issued on Nov. 27, 2001, and U.S. Utility Pat. Ser. No. 6,465,915 issued on Oct. 15, 2002, both owned by the assignee of the present invention, without making some structural modifications to the gear boxes.
Thus, it remains a problem in the prior art to keep a gear box and an L-shaped bracket secured together and attached to a wall inside a deployment apparatus for extending a safety device from a school bus.